Green transportation

New electrolysis cells pave the way for cheaper hydrogen

Ceramic electrolysis cells with new electrode material show promising durability. The cells can efficiently convert electricity into green fuels.

0,3 mm tynde keramiske elektrolyseceller med nye langtidsholdbare Ni-GDC elektroder indgår i stakke, hvor elektricitet kan spalte vand, som i form af damp sendes ind via store huller i kanten af stakkene.
Thin ceramic electrolysis cells (0.3 mm) containing new long-lasting Ni-GDC electrodes have been developed for integration in stacks where electricity can split water. The water is supplied as steam through large holes at the edge of the stacks. Photo Bax Lindhart.
Postdoc Morten Phan Klitkou shows Professor Henrik Lund Frandsen a ceramic electrode layer stretched on a plastic film. The different ceramic layers that make up the cell are glued together, after which the cells are cut into squares and fired at 1,250 degrees in a furnace. Photo: Bax Lindhardt.

Green transition

The production of hydrogen by electrolysis is a key part of the green transition, where the first step in any power-to-x, PtX process is always the production of hydrogen by electrolysis. In the future, we will have large amounts of power available from wind turbines and solar cells, including from the two energy islands to be built in the North Sea and on Bornholm. Much of the green electricity from the islands will be used to produce fuels for applications that are difficult to electrify, such as heavy road transportation, aviation, shipping, and a number of industrial processes.

Production of electrolysis cells

In Denmark, a lot of research and development of ceramic electrolysis cells has been carried out in a collaboration between the company Topsoe and researchers at DTU. In 2014, the parties entered into a non-exclusive license agreement that made it possible to manufacture and develop ceramic electrolysis cells (SOEC) in collaboration with DTU Energy. In 2023, this development led Topsoe to start construction of the world's first large scale factory to produce high-temperature electrolysis cells assembled in large numbers in so-called stacks in Herning. When the factory is completed in 2025, it will be able to produce 500 MW of electrolysis units annually, and by 2030, production will be expanded to 5 GW annually.

Henrik Lund Frandsen estimates that it will take up to ten years before the Ni-GDC electrolysis cells are fully scaled up and utilized in Power-to-X plants internationally.


The Ni-GDC fuel electrode and a number of other materials play crucial roles in an electrolysis cell that can produce hydrogen from water and electricity. The electrode used consists of nickel (Ni) and cerium oxide with added gadolinium (GDC). Cerium oxide is a ceramic material that can act as a transport channel for electricity and oxygen ions and, together with Ni, form a so-called electrode in these cells, where the electrical energy converts water (H₂O) into hydrogen (H₂) and oxygen (O₂).

The Ni-GDC electrode has several important functions in speeding up a chemical reaction, where the nickel catalyst on the surface of the electrode helps break down water molecules into hydrogen ions (H⁺) and oxygen ions (O²⁻), then the GDC is used to transport the oxygen ions. Once the process has produced green hydrogen, it can be stored or converted further and used as a carbon-neutral liquid fuel.


The transportation sector is emitting more and more CO2 from cars, trucks, planes and shipping. To reverse this trend, more of the known solutions and technologies need to come into play.

DTU is a leader in research and education in key technologies such as green electricity, green fuels, electrification of society and battery technology development.

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